Too many antibiotic prescriptions are inappropriate

Kao-Ping Chua, MD, PhD

Whereas it may not be a surprise that antibiotics are overprescribed, a new study reveals the extent of the problem, as well as the conditions and sources from which inappropriate antibiotic prescriptions originate.

The study, published in the BMJ, reveals that of 19.2 million antibiotics prescriptions written in 2016 for children and adults aged younger than 64 years, just 12.8% of outpatient fill were appropriate.

Led by Kao-Ping Chua, MD, PhD, assistant professor in the Department of Pediatrics and Communicable Diseases at the Child Health Evaluation and Research Center, University of Michigan, Ann Arbor, the study reviewed a total of 15 million antibiotics prescriptions fills for 19.2 million privately-insured patients aged between 0 and 64 years that received them in 2016. The research team reviewed patient information in the 3 days prior to the prescription being filled to determine why the antibiotic was necessary, and then classified each prescription written as appropriate or otherwise. Prescriptions were deemed "appropriate" for conditions in which antibiotics are always indicated; "potentially appropriate" in cases where antibiotics are sometimes indicated; or "inappropriate" when antibiotics are never indicated, such as in the treatment of a viral infection. The study also categorized some prescriptions as not being associated with a medical diagnosis-a category under which a quarter of the prescriptions fell.

Researchers also noted that the issue of inappropriate antibiotic use appears more rampant in adults than in children, with 25.2% of adult antibiotic prescriptions deemed inappropriate compared with 17.1% of antibiotic prescriptions filled for children.

“Our study shows that despite widespread quality improvement efforts, inappropriate antibiotic prescribing was still rampant in 2016,” Chua says. “The most common conditions were acute bronchitis and acute upper respiratory infections, or the common cold.”

Inappropriately written prescriptions

The study also revealed information about what types of antibiotics are being prescribed, for what conditions, and by what kinds of facilities. According to the report, azithromycin was the most commonly prescribed antibiotic at 19% of the total prescriptions, followed by amoxicillin with 18.2%, and amoxicillin-clavulanate at 11.6%. In all, 12.8% of these prescriptions were appropriate, 35.5% were deemed potentially appropriate, 23.2% were inappropriate, and 28.5% were not associated with a recent diagnostic code.

Although the study didn’t investigate the reason that inappropriate prescriptions were written, there is plenty of anecdotal data in that area.

“It’s hard to ascertain the rationale for prescribing using administrative data such as insurance claims,” Chua says. “However, we know from prior work that some of the factors that drive unnecessary prescriptions include a desire to satisfy patients, the fear of missing serious illnesses, and a lack of time to explain why antibiotics are unnecessary.”

Of the antibiotics prescriptions written appropriately, the study reveals that urinary tract infections, streptococcal pharyngitis/tonsillitis, and bacterial pneumonia were the most common diagnoses. Acute sinusitis, acute suppurative otitis media, and acute pharyngitis were the most common diagnoses for potentially appropriate prescriptions; and acute bronchitis, acute upper respiratory infections, and other respiratory symptoms such as cough were the most common diagnoses for inappropriate prescriptions, according to the report.

When considering the source of potentially inappropriately prescribed antibiotics, the study found that 74.7% were written in office-based settings, 7.8% in urgent care settings, and 6.6% in emergency departments (EDs). Inappropriate prescriptions were written in office-based settings 70.7% of the time, 6.2% of the time in urgent care settings, and 4.7 percent of the time in EDs.

“By themselves, these findings would show the widespread nature of the inappropriate outpatient antibiotic prescribing at the level of both prescription fill and population. However, 2 other findings in our study suggest that the true scope of inappropriate prescribing is even greater,” the researchers write. “First, among the 35.5% of fills classified as potentially appropriate, many could have been inappropriate. First example, 34.3% and 16.6% of fills in this category were associated with diagnosis of sinusitis and pharyngitis, respectively, and previous literature has shown that both these conditions have high rates of nonguideline-adherent antibiotic prescribing.”

Another 28.5% of fills not associated with a recent diagnosis code could also be added to the inappropriate fill list, the study notes.

“Collectively, fills that were potentially inappropriate or not associated with a recent diagnosis code represented 64% of all fills,” the researchers conclude. Chua says these numbers are concerning, especially in light of the problem of antibiotics resistance.

“Antibiotic prescribing is a primary driver of the development of bacteria that are resistant to antibiotics. The Centers for Disease Control and Prevention (CDC) estimates that every year, 2 million people in the United States develop infections with antibiotic-resistant bacteria, and 23,000 die,” Chua says. “I hope that our study reiterates the urgency for providers to eliminate inappropriate antibiotic prescribing, both for the sake of their own patients and for society more broadly.”

Chua says the study highlights the need for clinicians to write antibiotics prescriptions wisely, and to educate patients and parents on appropriate use.

“I think it’s important for clinicians not to assume that patients and families necessarily want antibiotics. Patients simply want to get better. In some cases, they may have a belief that antibiotics are the only way to get better, perhaps because they have been inappropriately prescribed antibiotics in the past for similar situations,” Chua says. “When this belief exists and the condition is clearly viral, it is important for clinicians to explain that patients will get better regardless of whether they receive antibiotics. At the same time, if they do get antibiotics, they risk [adverse] effects such as diarrhea, yeast infections, allergic reactions, and a transient increase in resistance to the antibiotic prescribed. In my experience, emphasizing that the risk-benefit ratio clearly favors not prescribing antibiotics can be a very persuasive tactic.”